Equipment for applying tape in a C-clip configuration is very well known and is commonplace in the literature and the industry. C-clip configuration generally applies a continuous ribbon of tape starting on a leading face of a case or carton passing through the machine along the surface of the case facing the taper and at least partway along the trailing face of the case i.e. the ribbon of tape forms a C-shape.
L-clip configuration generally applies a ribbon of tape along two adjacent a faces of case e.g. around a corner of the case i.e. the ribbon of tape is formed into an L-shape.
“L”-clip taping fulfills the “sustainability” packaging requirements in material and cost-saving comparing to the common “C”-clip taping. The concept of L-clip taping is known attention is directed to U.S. Pat. No. 4,640,731 that employs 2 separate applicators one to apply an L clip to the leading end and the other to apply an L clip to the trailing end of the case. U.S. Pat. No. 4,642,157 applies an L-clip using and application roll to apply the tape to one wall of the case and then a separate wipe down roll to apply the tape to an adjacent surface of the case. This device can only apply an L clip to the leading end of the case. Similarly U.S. Pat. No. 5,227,002 provides a device that can apply a tape in an L-clip configuration to leading face only of a case.
Majority of carton closure do not require a continuous C-clip tape to seal the full length of the flaps, particularly carton package for the domestic business to business market where the tape sealed cartons are stacked, palletized and pallet wrapped with plastic film for shipping and storage.
An L-clip configuration of a sealing tape is ideal for light weight cartons; single hinged flap cartons; tray carton with top lid; half slotted case, etc.
The L-clips generally may be peeled off easily by hand without the use of box cutting knife, eliminating injuries and product damages when opening the carton with knife.
In general, the adhesion and the strength of the pressure sensitive tape material are strong enough to withstand the weight of the content inside the carton with only the front and the back L-clips tape on top or at the bottom of the carton.
C-clip taping provides a more secure and dust/inserts/tamper proof package. It is ideal for individual consumer package subject to multi-handling and or over-sea shipping.
Regardless of all the obvious benefits of “L”-clip taping, the “C”-clip tape applicators are much more simple, reliable and user-friendly. Mostly operate mechanically without power-driven. They can be removed from the machine for tape replenishing with no tools. Because of its simplicity; low cost; easy to use and low maintenance as well as its long history of taping method, the popularity of C-clip taping remains very strong in the industry.
The currently available L-clip tape applicators in the industry are dedicated for L-clip taping only, mostly operated by air cylinder with electrical control, meaning external sensors wiring and two power sources are required. Mechanical non-powered L-clip tape applicators with separated front and back units are too complicated since it has two individual tape rolls and other duplicated apparatus (see U.S. Pat. No. 4,640,731 referred to above). They are not particularly user-friendly.
In general, L-clip tape applicators are much larger in size than conventional C-clip applicators and require more mounting space, extra wiring, special installation and a longer drive system to accommodate the tape applicator. Since the known L-clip tape applicators are dedicated for a single function, the carton sealing machine is dedicated for “L”-clip taping only. In situation where it is required to change the taping configuration, it is necessary to replace the entire tape applicator accordingly. The machine has to be shut down for the removal and disconnection of the existing unit and the installation, connection and set up of a different tape applicator.
The concept of a multifunctional taper capable (with minor adjustments) to apply a tape selectively in a C-clip or L-clip configuration is taught in Applicant's co-pending U.S. patent application Ser. No. 12/318,877 filed: Jan. 12, 2009 inventor Joe Lam the disclosure of which is incorporated herein by reference. This machine has the capability of selectively applying a C-clip, a L-clip or, a pair of L-clips (a leading and trailing L-Clip applied respectively to the lead or trailing end of the case being sealed or closed).
EPC application 0 259 241 describes a tape extender for extending the length of tape between a drag roll and the source of the tape (tape roll) and is an improvement for an apparatus for folding over the leading end of the tape to be applied to seal a carton in the conventional manner i.e. as a C-shaped tape application. This EPC Application 0 259 241 is specifically related to an apparatus for applying a length of tape and employs a drag between the tape supply roll and the lead applicator and operates to tension the tape between the supply roll and the drag as the tape is being pulled by movement of the case being taped and with the cut-off knife in inactive position and then to relieve said tension in the tape when the when the tape is cut by. cut off knife 150 in active cutting position.
The present invention provides an improved tape delivery system that is particularly suitable for delivering tape to a tape applicator for applying an L-clip to the case and provides a system for clamping and providing slack in the tape (extending the tape) being delivered to the point of application to the case.